This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Lynn Everett Genetic Diversity in Borrelia burgdorferi Borrelia burgdorferi, a tick-borne bacterium, is the causative agent of Lyme disease. There are currently a number of different approaches being used for development of a vaccine to prevent Lyme disease, one of which focuses on OspC, a bacterial outer surface protein. However, over 30 variations of the gene for this protein have been reported. This goal of this project is to aid in vaccine development by identifying the ospC variants of B. burgdorferi present in Delaware ticks. The approach is first to identify the variant of ospA present in each tick. There are only 4 of these variants, and they can be used to predict the presence of specific ospC variants, greatly reducing the number of reactions required. This will be done using PCR to amplify the appropriate regions of DNA, obtaining the DNA sequences of the amplified regions, and identifying the variants by computer-aided analysis of the sequences. The feasibility of screening human patients with Lyme disease in Delaware will also be investigated with an ultimate goal of determining which B. burgdorferi variants are responsible for infection.